KR100456303B1 - Reactor for the treatment of dyeing waste water by electrochemical oxidation-reduction reaction and method for the treatment of dyeing waste water using the same - Google Patents

Abstract

A main body having an inlet for dyeing wastewater flowing in, a sludge discharge hole for discharging sludge discharged, and an outlet for discharged treated wastewater discharged; A cathode and an anode provided in the main body and made of an alloy containing 5 to 30% by weight of Fe 70 to 95% by weight and at least one metal selected from the group consisting of Ti, Ni, and Al; Dyeing wastewater treatment reactor and dyeing wastewater treatment method using the reactor, characterized in that it comprises a power supply for supplying power to the cathode and the anode. According to such a dyeing wastewater treatment reactor and treatment method, wastewater treatment can be performed by using a wastewater treatment device having the advantages of simplifying the reactor structure, eliminating the need for chemical coagulants, using a minimum amount of electric energy, and generating a minimum amount of sludge.

Description

Reactor for the treatment of dyeing waste water by electrochemical oxidation-reduction reaction and method for the treatment of dyeing waste water using the same}

The present invention relates to a dyeing wastewater treatment reactor and a dyeing wastewater treatment method using the same, and more specifically, a dyeing wastewater treatment reactor capable of precipitating and removing dyes in dyeing wastewater by an electrochemical oxidation-reduction reaction, and using the same. It relates to a dye wastewater treatment method.

Dyeing wastewater has a large difference in dyeing methods depending on the material to be dyed, and the composition of the dye is generally very complicated because the types of dyes and mordants used are different depending on the dyeing method and color tone of the same fiber. In addition, the contaminants in the wastewater include dyes, mordants, basophils, reducing agents, and the like, and a large amount of detergents used to remove the agents. Among these, biologically easy materials are only acetic acid and some detergents used as starch and flocculant. The remainder is generally poorly biodegradable, and dyes are often toxic and inhibitory to organisms.

Because of the complex composition of dyeing wastewater and the large fluctuations in water quality, various treatment methods and combinations thereof have been examined, but it is difficult to develop an accurate treatment system. Among the emission standards for wastewater strengthened by existing treatment facilities, especially the chromaticity is the biggest problem because it is difficult to aggregate, oxidize or decompose by physicochemical treatment.

In the case of soluble dyes in wastewater treatment plants in Korea, there is a general problem that it is difficult to completely remove the chromaticity only by flocculation by chemicals. Therefore, in order to solve the more fundamental color problem, it is necessary to develop an active method of destroying chromophores or dissolving and removing chromophores.

In general, the treatment of dyeing wastewater has a pretreatment process in which strong acids such as sulfuric acid are used to remove chemically aggregated-precipitable substances and then remove components that are toxic to microorganisms through physical coagulation-precipitation reactions. The thing about chromaticity is difficult to remove through this pretreatment process. Conventionally, the chromophore of the dye can be oxidized or reduced by electrolysis using electrolysis. However, this method is basically different from the chemical oxidation-reduction method and has a disadvantage of requiring a lot of electrical energy.

The most widely used method of biologically treating dye wastewater is activated sludge method, which is a method of adsorbing or decomposing organic matter by activated aerobic microorganisms. However, the above method has a disadvantage in that a large amount of sludge is generated and solid-liquid separation in a sedimentation tank is not good. In addition, the dyes in the dyeing waste water are composed of materials that are difficult to decompose biologically most of the dyes are not well decomposed, and even if decomposed, there is a disadvantage that adversely affect the treatment efficiency because it can generate toxic substances.

In order to remove the chromaticity of dyeing wastewater, the most common wastewater treatment method is the integrated treatment of wastewater generated in a factory in a batch process. However, this method is suitable for the treatment of domestic wastewater and domestic sewage, which has many problems in treating highly concentrated and hardly degradable dyed wastewater and is known as an inefficient treatment method.

The most preferable method is to classify and treat the wastewater generated by each process, which requires a lot of additional equipment investment and requires a treatment cost because it requires linking process by process. This batch integrated treatment method is a treatment method that is difficult to be practical in practice because it is possible to completely separate the discharge, the mordant, detergent, dye, etc. by each process.

Therefore, the technical problem of the present invention is to overcome the limitations of the chemical bleaching method, physical bleaching method and biological treatment method, without using a separate chemical coagulant, using a small amount of electrical energy, a small amount of sludge It is an object of the present invention to provide a reactor for treating dyed wastewater having an advantage of generating sludge.

In addition, the technical problem to be achieved by the present invention is to provide a method for treating the dyeing wastewater using the reactor as described above.

Figure 1 is a schematic diagram showing the mechanism of the aggregation-precipitation reaction of the dye by the electrochemical oxidation-reduction reaction in the reactor according to the present invention.

2 is a perspective view schematically showing a reactor according to the present invention.

Figure 3 compares the treatment efficiency of BOD, COD, total nitrogen, total phosphorus, chromaticity according to the reaction time of the dye wastewater.

<Explanation of symbols for the main parts of the drawings>

10: reactor 11: power supply

12: Transition of cathode and anode 13: cathode

14: anode 15: inlet

16: outlet 17: sludge outlet

In order to achieve the above technical problem, the present invention

A main body having an inlet for dyeing wastewater flowing in, a sludge discharge hole for discharging sludge discharged, and an outlet for discharged treated wastewater discharged;

A cathode and an anode provided in the main body and made of an alloy containing 5 to 30% by weight of Fe 70 to 95% by weight and at least one metal selected from the group consisting of Ti, Ni, and Al;

It provides a dyeing wastewater treatment reactor comprising a power supply for supplying power to the cathode and the anode.

The dyeing wastewater treatment reactor according to the present invention as described above preferably further comprises an electrode converter for electrically converting the cathode and the anode.

In the dye wastewater treatment reactor according to the present invention as described above, the anode and the cathode is preferably made of an alloy containing all of Fe, Ti, Ni and Al.

In order to achieve the above another technical problem, the present invention

a) a cathode and an anode composed of an alloy comprising from 70 to 95% by weight of Fe and from 5 to 30% by weight of at least one metal selected from the group consisting of Ti, Ni and Al; And introducing the dye wastewater into the dye wastewater treatment reactor including an electrode converter for electrically converting the cathode and the anode; And

b) supplying power to the cathode and the anode such that the iron ions detached from the electrode and the oxidized or reduced dye react and precipitate by electrochemical oxidation-reduction reaction while the dyeing wastewater contacts the electrode. It provides a dyeing wastewater treatment method characterized by.

In the dyeing wastewater treatment method according to the present invention as described above, it is preferable to use a DC voltage power supply of 1 to 10 volts as the power supply of step b).

In the dye wastewater treatment method according to the present invention as described above, it is preferable to further include the step of electrically converting the cathode and the anode repeatedly at a predetermined time interval using the electrode converter of the reactor.

Hereinafter, the dyeing wastewater treatment reactor and the dyeing wastewater treatment method according to the present invention will be described in more detail with reference to the accompanying drawings.

Referring to FIG. 1 which is a schematic diagram showing the mechanism of the aggregation-precipitation reaction of the dye by the electrochemical oxidation-reduction reaction made in the reactor according to the present invention, and FIG. 2 which is a perspective view schematically showing the reactor according to the present invention, Dye wastewater treatment reactor according to the invention comprises a power supply 11, the cathode 13 and the electrical converter 12 of the anode 14, the cathode 13 and the anode (14). In addition, the reactor according to the present invention includes an inlet 15 through which the dyeing wastewater is introduced, an outlet 16 through which the treated wastewater is discharged, and an outlet 17 through which the settling sludge is discharged. The position and shape of the inlet 15, the outlet 16 and the sludge outlet 17 can be applied to the present invention all known in the art to which the present invention pertains, without being particularly limited.

The cathode 13 and the anode 14 are 70 to 95% by weight of iron (Fe) and 5 to 30% by weight of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni) and aluminum (Al). It is composed of an alloy comprising the dye can be actively redox at the electrode surface at a low voltage of 1 to 10 volts, preferably 2 to 5 volts.

Titanium and nickel added to the alloy for manufacturing the cathode 13 and the anode 14 have a lower oxidation-reduction potential than iron to catalyze the transfer of electrons, and aluminum has a higher oxidation-reduction potential than iron. As used as an oxidation promoter to promote the oxidation reaction of these, they can be used freely selected combinations in the above-described content in the range, if necessary, preferably includes all of titanium, nickel and aluminum. This is because by including all of them, both oxidation and reduction of the dye on the electrode surface can be promoted.

Oxidation of iron in the cathode 13 promotes the production of iron ions and at the same time promotes oxidation of the dye. Oxidized dyes are surrounded by a positively charged, negatively polarized water molecule, hydrated and then combined with positive iron ions to agglomerate, and dye reduction at anode 14 promotes the production of dye anions and positive iron Aggregates in combination with warm. If the dye is completely oxidized or reduced and no further redox reaction occurs, the oxidation of iron is stopped due to the decrease of the charge amount. When iron is oxidized, phenomena involving oxidation of dyes can be observed by changing the amount of current.

The electrode, that is, the cathode 13 and the anode 14 is installed in the reactor and connected to the external power supply 11, 1 to 10 volts to the cathode 13 and the anode 14 during the reaction, It is preferably configured to maintain the potential difference using a DC voltage of 2 to 5 volts.

1 to 2, the dyeing wastewater treatment reactor according to the present invention includes a converter 12 for electrically converting the cathode and the anode, and the converter 12 is a reactor according to the present invention. As an additional addition of, it is advantageous to disperse the redox reaction at the electrode surface by installing it and switching the cathode 13 and the anode 14 at regular time intervals. That is, if the converter 12 is not present, the iron of the cathode 13 is continuously oxidized until the reaction is completed to be released to the iron ions, so that only the cathode 13 is exhausted rapidly, but the converter 12 When installed, the cathode 13 and the anode 14 are switched so that both electrodes are exhausted evenly, thereby extending the life of the electrode. The time period for converting the cathode and the anode by using the converter 12 is appropriately adjusted in consideration of the treatment capacity of the reactor, the amount of the dyeing wastewater introduced, etc. if one of ordinary skill in the art. Can be.

In addition, the sludge formed by the reaction of the iron ions and the dye is precipitated is discharged through the sludge outlet 17, the sludge outlet 17 can take the natural fall method by gravity, and is forced by the discharge pump It can also take the way of discharge.

In the present invention as described above, the effluent after the treatment through the other dye wastewater treatment reactor can be discharged to the stream immediately when the COD content of the original dye wastewater is low, but the COD content of the original dye wastewater introduced In this high case (typically 1,000 or more), it is not immediately discharged into a river or the like, but more biologically treated and then released into a river or the like. In the case where it is necessary to go through the biological treatment, etc., since the dyeing wastewater is strongly alkaline, it is necessary to send the effluent flowing out through the reactor according to the present invention to the pH adjusting tank to adjust the pH to neutral to facilitate the biological treatment. .

Therefore, the dyeing wastewater treatment reactor according to the present invention can be used for single treatment for low concentration dyeing wastewater, and for pretreatment such as biological treatment for high concentration dyeing wastewater.

Hereinafter, the present invention will be described in more detail with reference to Examples. Since these examples are only for illustrating the present invention, the scope of the present invention is not to be construed as being limited by these examples.

Example 1

Treatment of Dyeing Dye Wastewater Collected from Sewage Tanks at Dyeing Plant located in Daegu Dyeing Complex

This embodiment was carried out in the following manner.

The collected wastewater was transferred to the reactor using a metering pump (Watson & Marlow Model 505s) without pH adjustment. The treatment capacity of the reactor was 20 liters, and the electrode was made of an alloy consisting of 70% by weight of iron, 10% by weight of titanium, 10% by weight of nickel, and 10% by weight of aluminum. The residence time was adjusted from 3 hours to 25 hours by adjusting the feed rate of the metering pump.

The electrode was connected to a power supply (model: HANIL HPS-3010B, T & B co.), And configured to maintain a potential difference using a DC voltage of about 2 to 3 volts at the cathode and anode during the reaction. Was maintained at 8 to 9 amperes.

In addition, a relay and a timer were installed so that the cathode and the anode could be electrically switched at intervals of 10-20 minutes, and the sludge was settled by forced discharge through a discharge pump.

The treated supernatant was allowed to flow out through the outlet of the reactor, and the outflow method through the outlet used a natural dropping method due to a high difference.

The treated supernatant was sampled according to the residence time to measure BOD, COD, total nitrogen, total phosphorus, and chromaticity. The results are shown in FIG. 3.

Chromaticity, COD, total phosphorus and total nitrogen were analyzed using HACH DR-4000, and BOD was analyzed manually using standard methods (process test method, publishing company editorial technology editorial, 1998 edition, 5th edition).

Referring to FIG. 3, the treatment efficiency was 80 to 85% for the 8 hour residence time, and 90 to 95% for the 12 hour residence time, and the treatment efficiency increased significantly after 3 hours. In the case of treatment for more than 12 hours, treatment efficiency did not increase significantly with treatment time.

<Example 2>

Treatment of Dye Wastewater Collected by Dyeing Wastewater Treatment Plant of Daegu Dyeing Complex

In this example, the dyeing wastewater treatment reactor and treatment method were the same as in Example 1, and the residence time was adjusted to 12 hours.

In addition, the treated effluent was sampled and measured for BOD, COD, total nitrogen, total phosphorus, chromaticity and suspended solids, and the results are shown in Table 1 below.

In addition, the effluent was transferred to a biological treatment tank and treated with activated sludge, and then measured for BOD, COD, total nitrogen, total phosphorus, color, and suspended solids. The results are also shown in Table 1 below. It was time.

In addition, the dyeing wastewater collected from the Daegu Dyeing Wastewater Treatment Plant immediately after treatment with activated sludge method without electrochemical treatment according to the present invention was measured for COD, total nitrogen, total phosphorus and the results are also shown in Table 1 below. In this case, the residence time was 12 hours.

sample COD BOD Chromaticity Total nitrogen A total person Suspended solids Residence time enemy 1121.1 305.5 5275 975.0 17.7 38.5 Treatment according to the present invention 108.4 30.5 500.4 164.0 2.9 3.5 12 Activated sludge treatment after treatment according to the present invention 55.4 5.5 128.0 16.5 2.6 3.2 12 Activated Sludge Process Treatment 399 26.8 74.9 12 unit mg / L

As can be seen from Table 1, the BOD, COD, total nitrogen, As a result of comparing total phosphorus, chromaticity and suspended solids content before and after the treatment, the overall treatment efficiency was 95-98%. Also, in the case of biological treatment after the electrochemical treatment according to the present invention, the biological treatment was performed directly without electrochemical pretreatment. Compared with the case of treatment, the overall efficiency was increased by 5-8 times compared to the reactor.

In addition, in order to compare the treatment efficiency of the present invention with conventional treatment methods, the results of treatment with the Fenton oxidation method, the chemical aggregation method and the ozone treatment method are shown in Table 2 below.

The Fenton oxidation method, chemical coagulation method and ozone treatment method were carried out according to the conventional methods with reference to papers and water treatment related books. [Reference book: Environmental Chemistry (Published by Donghwa, Author: Kim Deok-chan, etc.), Water treatment experiment for published : Donghwa Technology, Translation: Nam-cheon Kim, et al.), Industrial Wastewater Treatment Engineering (Published by Donghwa Technology, Author: Lim, Jem-myung, etc.), Reference Papers: Treatment Characteristics of Paper Wastewater Using the Fenton and H2O2 / UV Processes].

sample COD BOD Chromaticity Total nitrogen A total person Suspended solids Residence time enemy 1121.1 305.5 5275 975.0 17.7 38.5 Treatment according to the invention 108.4 30.5 500.4 164.0 2.9 3.5 12 Fenton Oxidation 123 41.8 395 255 7.8 1.8 3 Chemical flocculation 886 145 4800 444 13 2.9 6 Ozone oxidation 1112 299 2100 895 16 6.9 15 unit mg / L

In the results of Table 2, the chemical agglomeration method, the overall efficiency of the treatment compared to the electrochemical treatment method according to the present invention was less than 50%, the effect of removing the chromaticity was less than 10%. In addition, in the Fenton oxidation method, the removal efficiency of chromaticity was 105% compared to the treatment efficiency of the present invention, but the overall treatment efficiency was 90%. The ozone oxidation method was less than 30% in total compared with the treatment efficiency of the present invention. Therefore, it can be seen that the treatment method according to the present invention is considerably superior in terms of treatment efficiency than the conventional treatment method.

<Example 3>

Comparison of sludge generation after treatment

In order to compare the amount of sludge generated, the sludge produced after the experiment as in Example 1 was placed in a mass cylinder of 30 liter capacity and allowed to stand for 24 hours to confirm the volume of sediment, and the sludge was Watman No.1 filter. After stirring for 12 hours at room temperature, the weight was taken as the non-dry weight. The non-dried sludge was incinerated at 1200 ° C. for 12 hours, and then the weight was measured and used as the weight value after incineration, and the measurement results are shown in Table 2.

In addition, in order to compare the amount of sludge generated in the treatment method according to the present invention with the conventional method, the same amount of the same wastewater was treated by the Fenton oxidation method and the chemical condensation method so that the same treatment efficiency as the treatment according to the present invention. After the same method was measured and the results are also shown in Table 2.

The organic coagulants used for fenton oxidation and chemical coagulation were cationic C-64 and anionic HAP-525 using 1-2 g / L. The hydrogen peroxide used for fenton oxidation was 2g / L and the iron oxide was 12g / L, exceeding 60 times the capacity normally used, which was experimentally obtained after obtaining experimental values in proportion to the COD load of the raw wastewater (about 2000mg / L). Is the amount used. Alumina sulfate used for chemical coagulation was 3 g / L, more than 10 times more than the amount generally used to increase the treatment efficiency.

Treatment method Liter of Raw Water COD of raw water (mg / L) Sludge volume after treatment Weight of undried sludge (kg) Weight after sludge incineration (g) Treatment according to the present invention 100 1980 14 12 390 Fentone Oxidation 100 1980 24 21 1240 Chemical coagulation 100 1980 32 24 85

As a result of comparing the sludge generation after the treatment, as shown in Table 3, it can be seen that the amount of sludge generated by the treatment method according to the present invention was significantly reduced than that by the chemical flocculation method or the Fentone oxidation method.

As described above, according to the present invention, low-energy, low-sludge generation, and high-treatment efficiency can be realized by replacing various physical and chemical treatments such as Fenton oxidation, chemical coagulation, ozone treatment, high frequency treatment, and filtration without additives. . Furthermore, environmental pollution can be prevented. In addition, the dyeing wastewater treated in this way is not toxic to microorganisms, so it can be post-treated by activated sludge method. In addition, according to the present invention, since the electrical energy is also operated at a low voltage of 1 to 10 volts, preferably 2 to 5 volts, there is no safety risk and power consumption is about 5 W / liter / day, which leads to low energy consumption.

Claims (6)

A main body having an inlet for dyeing wastewater flowing in, a sludge discharge hole for discharging sludge discharged, and an outlet for discharged treated wastewater discharged; A cathode and an anode provided in the main body and made of an alloy containing 5 to 30% by weight of Fe 70 to 95% by weight and at least one metal selected from the group consisting of Ti, Ni, and Al; Reactor for dyeing wastewater treatment, characterized in that it comprises a power supply for supplying power to the cathode and the anode. The reactor for treating dye wastewater according to claim 1, further comprising an electrode converter for electrically converting the cathode and the anode. The reactor for treating dye wastewater according to claim 1, wherein the anode and the cathode are made of an alloy containing all of Fe, Ti, Ni, and Al. a) a cathode and an anode composed of an alloy comprising from 70 to 95% by weight of Fe and from 5 to 30% by weight of at least one metal selected from the group consisting of Ti, Ni and Al; And introducing the dye wastewater into the dye wastewater treatment reactor including an electrode converter for electrically converting the cathode and the anode; And b) supplying power to the cathode and the anode such that the iron ions detached from the electrode and the oxidized or reduced dye react and precipitate by electrochemical oxidation-reduction reaction while the dyeing wastewater contacts the electrode. Dyeing wastewater treatment method characterized in that. The method of claim 4, wherein the power source of step b) is a 1 to 10 volts DC voltage power supply. The method of claim 4 or 5, further comprising the step of electrically converting the cathode and the anode repeatedly at a predetermined time interval using the electrode changer of the reactor.